Field of the Invention
The present invention relates to apparatus for testing an aircraft brake disc.
Description of the Related Art
In general, when aircrafts are landing, wheels come out under the body, land and rotate on a runway, and are then stopped by braking force generated by brake assemblies in the wheels. An example of aircraft brake disc assemblies has been disclosed in U.S. Pat. No. 7,900,751 B2 (registered on Mar. 8, 2011).
An aircraft brake disc is composed of a pressure disc, a rear disc, and rotary discs and fixing discs that are alternately disposed between the pressure disc and the rear disc. The rotary disc is coupled to a drive key of a wheel frame of an aircraft and rotates with the wheel frame. The fixing disc is coupled to the splines of a torque tube included in an aircraft brake system, so it does not rotate with the wheel frame of an aircraft.
According to an aircraft brake disc assembly, when it is operated, a hydraulic piston pushes the pressure disc by hydraulic pressure. As the hydraulic piston pushes the pressure disc, the rotary disc and the fixing disc are pressed to each other between the pressure disc and the rear disc that is fixed. The rotary discs decelerated and stopped by friction between the rotary disc and the fixing disc. The wheel frame and the wheel of the aircraft that are rotated with the rotary disc are also decelerated and stopped.
The pressure disc, the rear disc, the rotary disc, and the fixing disc increase in temperature over 1000° C. due to friction therebetween, when an aircraft is landing. The pressure disc, the end disc, the rotary disc, and the fixing disc are made of a carbon-carbon composite to maintain friction or mechanical strength against the high temperature. The carbon-carbon composite is a material that keeps friction or mechanical strength even at a high temperature over 2500° C. and has excellent resistance against thermal shock and excellent thermal conductivity.
The braking performance of aircraft brake discs are tested, after they are manufactured.
A “tester for characteristic evaluation of brake friction material for aircraft” has been disclosed in Korean Patent No. 10-0184791 (Registered on Dec. 21, 1998) (hereinafter, referred to as a prior art). However, according to the prior art, only a brake disc assembly except a tire is tested, so similar conditions when an aircraft is landing is not implemented and an exact test cannot be achieved. Further, the apparatus is not suitable for testing aircraft wheels having various sizes.